Turbomachines are widely utilized in fields such as power generation. For example, a conventional gas turbine system includes a compressor section, a combustor section, and at least one turbine section. The compressor section is configured to compress air as the air flows through the compressor section. The air is then flowed from the compressor section to the combustor section, where it is mixed with fuel and combusted, generating a hot gas flow. The hot gas flow is provided to the turbine section, which utilizes the hot gas flow by extracting energy from it to power the compressor, an electrical generator, and other various loads.
A turbomachine is typically coupled with an accessory assembly (which may provide and monitor, for example, fluids supplied to the turbomachine) to form a turbomachine assembly. In the field, it is typically desirable to shield the turbomachine assembly from external environmental factors, such as rain, dust, heat, wind, etc. Additionally, it is desirable to reduce the noise generated by the turbomachine assembly and to protect operators in case of accidents such as, for example, fire or explosion. Accordingly, at least one component of the turbomachine assembly, such as the turbomachine and/or the accessory assembly or assemblies, may be housed within an enclosure.
Within the enclosure, elevated temperatures can cause regulating devices and sensors within the enclosure to malfunction or fail. Additionally, gas leaks can occur from the turbomachine into the enclosure. Accordingly, ventilation components are utilized with the enclosure to form a ventilation system housing the component(s) of the turbomachine assembly. The ventilation system can generally remove heat from and dilute gas in the enclosure.
A ventilation system typically includes a gas leak detection system, which can be installed for example in an air outlet circuit of the system. The gas leak detection system generally detects gas leaks in the enclosure and monitors the leaks relative to predetermined levels in order to avoid explosion risks, etc. The ventilation system further generally produces at least a minimum air flow therethrough to ensure sufficient flow through the air outlet circuit such that the gas leak detection system functions properly. If gas levels in the enclosure exceed predetermined levels, the turbomachine may be designed to trip, such that the fuel supply to the turbomachine is cut off.
Currently, various mechanical devices are utilized to measure air flow in the ventilation system, to ensure that a sufficient air flow level is occurring in the ventilation system to provide sufficient ventilation. If the air flow in the system drops below a minimum level, the turbomachine may be designed to trip. The mechanical devices may, for example, measure velocity and/or relative pressure in the air inlet circuit and air outlet circuit of the system. However, the use of mechanical devices can have various drawbacks, and can lead in some cases to false low air flow measurements. For example, the local effects of wind speed increases and wind directions changes, such as during storms, as well as other climatic disturbances, can lead to faulty air flow measurements. While time delays before tripping have been utilized in an attempt to reduce the impact of such faulty air flow measurements, most local effects that cause such faulty measurements occur for periods of time that are longer than the prescribed time delays. Longer time delays would increase the risk of explosion, etc. if an actual low air flow event were to occur. Additionally, while walls and/or various other protection systems have been utilized to shield the ventilation system from such climatic disturbances, these systems can be expensive, inefficient, and in many case insufficient.
Accordingly, improved ventilation systems and methods for monitoring air flow in ventilation systems for turbomachine assemblies are desired in the art. In particular, systems and methods which provide improved low air flow detection by reducing or preventing false low air flow measurements would be advantageous.